Which substance is NOT considered an opioid?

Acetaminophen is not considered an opioid because it operates through a different mechanism than opioids. While opioids are derived from the opium poppy or synthesized to mimic these compounds and primarily act by binding to opioid receptors in the brain and spinal cord to relieve pain, acetaminophen has a different action. Its exact mechanism is not fully understood, but it is believed to reduce pain and fever by acting on the central nervous system and inhibiting certain pathways related to the perception of pain. This distinction is crucial in clinical practice, where understanding the classification of pain medications helps guide appropriate treatment choices for patients based on their specific needs and conditions.